block/parallels.c

   1 /*
   2  * Block driver for Parallels disk image format
   3  *
   4  * Copyright (c) 2007 Alex Beregszaszi
   5  * Copyright (c) 2015 Denis V. Lunev <den@openvz.org>
   6  *
   7  * This code was originally based on comparing different disk images created
   8  * by Parallels. Currently it is based on opened OpenVZ sources
   9  * available at
  10  *     http://git.openvz.org/?p=ploop;a=summary
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a copy
  13  * of this software and associated documentation files (the "Software"), to deal
  14  * in the Software without restriction, including without limitation the rights
  15  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  16  * copies of the Software, and to permit persons to whom the Software is
  17  * furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included in
  20  * all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  25  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  26  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  27  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  28  * THE SOFTWARE.
  29  */
  30 #include "qemu-common.h"
  31 #include "block/block_int.h"
  32 #include "qemu/module.h"
  33
  34 /**************************************************************/
  35
  36 #define HEADER_MAGIC "WithoutFreeSpace"
  37 #define HEADER_MAGIC2 "WithouFreSpacExt"
  38 #define HEADER_VERSION 2
  39 #define HEADER_INUSE_MAGIC  (0x746F6E59)
  40
  41 #define DEFAULT_CLUSTER_SIZE 1048576        /* 1 MiB */
  42
  43
  44 // always little-endian
  45 typedef struct ParallelsHeader {
  46     char magic[16]; // "WithoutFreeSpace"
  47     uint32_t version;
  48     uint32_t heads;
  49     uint32_t cylinders;
  50     uint32_t tracks;
  51     uint32_t bat_entries;
  52     uint64_t nb_sectors;
  53     uint32_t inuse;
  54     uint32_t data_off;
  55     char padding[12];
  56 } QEMU_PACKED ParallelsHeader;
  57
  58 typedef struct BDRVParallelsState {
  59     /** Locking is conservative, the lock protects
  60      *   - image file extending (truncate, fallocate)
  61      *   - any access to block allocation table
  62      */
  63     CoMutex lock;
  64
  65     ParallelsHeader *header;
  66     uint32_t header_size;
  67     bool header_unclean;
  68
  69     uint32_t *bat_bitmap;
  70     unsigned int bat_size;
  71
  72     unsigned int tracks;
  73
  74     unsigned int off_multiplier;
  75
  76     bool has_truncate;
  77 } BDRVParallelsState;
  78
  79
  80 static int64_t bat2sect(BDRVParallelsState *s, uint32_t idx)
  81 {
  82     return (uint64_t)le32_to_cpu(s->bat_bitmap[idx]) * s->off_multiplier;
  83 }
  84
  85 static int64_t seek_to_sector(BDRVParallelsState *s, int64_t sector_num)
  86 {
  87     uint32_t index, offset;
  88
  89     index = sector_num / s->tracks;
  90     offset = sector_num % s->tracks;
  91
  92     /* not allocated */
  93     if ((index >= s->bat_size) || (s->bat_bitmap[index] == 0)) {
  94         return -1;
  95     }
  96     return bat2sect(s, index) + offset;
  97 }
  98
  99 static int cluster_remainder(BDRVParallelsState *s, int64_t sector_num,
 100         int nb_sectors)
 101 {
 102     int ret = s->tracks - sector_num % s->tracks;
 103     return MIN(nb_sectors, ret);
 104 }
 105
 106 static int64_t allocate_cluster(BlockDriverState *bs, int64_t sector_num)
 107 {
 108     BDRVParallelsState *s = bs->opaque;
 109     uint32_t idx, offset;
 110     int64_t pos;
 111     int ret;
 112
 113     idx = sector_num / s->tracks;
 114     offset = sector_num % s->tracks;
 115
 116     if (idx >= s->bat_size) {
 117         return -EINVAL;
 118     }
 119     if (s->bat_bitmap[idx] != 0) {
 120         return bat2sect(s, idx) + offset;
 121     }
 122
 123     pos = bdrv_getlength(bs->file) >> BDRV_SECTOR_BITS;
 124     if (s->has_truncate) {
 125         ret = bdrv_truncate(bs->file, (pos + s->tracks) << BDRV_SECTOR_BITS);
 126     } else {
 127         ret = bdrv_write_zeroes(bs->file, pos, s->tracks, 0);
 128     }
 129     if (ret < 0) {
 130         return ret;
 131     }
 132
 133     s->bat_bitmap[idx] = cpu_to_le32(pos / s->off_multiplier);
 134     ret = bdrv_pwrite(bs->file,
 135             sizeof(ParallelsHeader) + idx * sizeof(s->bat_bitmap[idx]),
 136             s->bat_bitmap + idx, sizeof(s->bat_bitmap[idx]));
 137     if (ret < 0) {
 138         s->bat_bitmap[idx] = 0;
 139         return ret;
 140     }
 141     return bat2sect(s, idx) + offset;
 142 }
 143
 144 static int64_t coroutine_fn parallels_co_get_block_status(BlockDriverState *bs,
 145         int64_t sector_num, int nb_sectors, int *pnum)
 146 {
 147     BDRVParallelsState *s = bs->opaque;
 148     int64_t offset;
 149
 150     qemu_co_mutex_lock(&s->lock);
 151     offset = seek_to_sector(s, sector_num);
 152     qemu_co_mutex_unlock(&s->lock);
 153
 154     *pnum = cluster_remainder(s, sector_num, nb_sectors);
 155
 156     if (offset < 0) {
 157         return 0;
 158     }
 159
 160     return (offset << BDRV_SECTOR_BITS) |
 161         BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
 162 }
 163
 164 static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
 165         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
 166 {
 167     BDRVParallelsState *s = bs->opaque;
 168     uint64_t bytes_done = 0;
 169     QEMUIOVector hd_qiov;
 170     int ret = 0;
 171
 172     qemu_iovec_init(&hd_qiov, qiov->niov);
 173
 174     while (nb_sectors > 0) {
 175         int64_t position;
 176         int n, nbytes;
 177
 178         qemu_co_mutex_lock(&s->lock);
 179         position = allocate_cluster(bs, sector_num);
 180         qemu_co_mutex_unlock(&s->lock);
 181         if (position < 0) {
 182             ret = (int)position;
 183             break;
 184         }
 185
 186         n = cluster_remainder(s, sector_num, nb_sectors);
 187         nbytes = n << BDRV_SECTOR_BITS;
 188
 189         qemu_iovec_reset(&hd_qiov);
 190         qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
 191
 192         ret = bdrv_co_writev(bs->file, position, n, &hd_qiov);
 193         if (ret < 0) {
 194             break;
 195         }
 196
 197         nb_sectors -= n;
 198         sector_num += n;
 199         bytes_done += nbytes;
 200     }
 201
 202     qemu_iovec_destroy(&hd_qiov);
 203     return ret;
 204 }
 205
 206 static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
 207         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
 208 {
 209     BDRVParallelsState *s = bs->opaque;
 210     uint64_t bytes_done = 0;
 211     QEMUIOVector hd_qiov;
 212     int ret = 0;
 213
 214     qemu_iovec_init(&hd_qiov, qiov->niov);
 215
 216     while (nb_sectors > 0) {
 217         int64_t position;
 218         int n, nbytes;
 219
 220         qemu_co_mutex_lock(&s->lock);
 221         position = seek_to_sector(s, sector_num);
 222         qemu_co_mutex_unlock(&s->lock);
 223
 224         n = cluster_remainder(s, sector_num, nb_sectors);
 225         nbytes = n << BDRV_SECTOR_BITS;
 226
 227         if (position < 0) {
 228             qemu_iovec_memset(qiov, bytes_done, 0, nbytes);
 229         } else {
 230             qemu_iovec_reset(&hd_qiov);
 231             qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
 232
 233             ret = bdrv_co_readv(bs->file, position, n, &hd_qiov);
 234             if (ret < 0) {
 235                 break;
 236             }
 237         }
 238
 239         nb_sectors -= n;
 240         sector_num += n;
 241         bytes_done += nbytes;
 242     }
 243
 244     qemu_iovec_destroy(&hd_qiov);
 245     return ret;
 246 }
 247
 248
 249 static int parallels_check(BlockDriverState *bs, BdrvCheckResult *res,
 250                            BdrvCheckMode fix)
 251 {
 252     BDRVParallelsState *s = bs->opaque;
 253     int64_t size, prev_off, high_off;
 254     int ret;
 255     uint32_t i;
 256     bool flush_bat = false;
 257     int cluster_size = s->tracks << BDRV_SECTOR_BITS;
 258
 259     size = bdrv_getlength(bs->file);
 260     if (size < 0) {
 261         res->check_errors++;
 262         return size;
 263     }
 264
 265     if (s->header_unclean) {
 266         fprintf(stderr, "%s image was not closed correctly\n",
 267                 fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
 268         res->corruptions++;
 269         if (fix & BDRV_FIX_ERRORS) {
 270             /* parallels_close will do the job right */
 271             res->corruptions_fixed++;
 272             s->header_unclean = false;
 273         }
 274     }
 275
 276     res->bfi.total_clusters = s->bat_size;
 277     res->bfi.compressed_clusters = 0; /* compression is not supported */
 278
 279     high_off = 0;
 280     prev_off = 0;
 281     for (i = 0; i < s->bat_size; i++) {
 282         int64_t off = bat2sect(s, i) << BDRV_SECTOR_BITS;
 283         if (off == 0) {
 284             prev_off = 0;
 285             continue;
 286         }
 287
 288         /* cluster outside the image */
 289         if (off > size) {
 290             fprintf(stderr, "%s cluster %u is outside image\n",
 291                     fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
 292             res->corruptions++;
 293             if (fix & BDRV_FIX_ERRORS) {
 294                 prev_off = 0;
 295                 s->bat_bitmap[i] = 0;
 296                 res->corruptions_fixed++;
 297                 flush_bat = true;
 298                 continue;
 299             }
 300         }
 301
 302         res->bfi.allocated_clusters++;
 303         if (off > high_off) {
 304             high_off = off;
 305         }
 306
 307         if (prev_off != 0 && (prev_off + cluster_size) != off) {
 308             res->bfi.fragmented_clusters++;
 309         }
 310         prev_off = off;
 311     }
 312
 313     if (flush_bat) {
 314         ret = bdrv_pwrite_sync(bs->file, 0, s->header, s->header_size);
 315         if (ret < 0) {
 316             res->check_errors++;
 317             return ret;
 318         }
 319     }
 320
 321     res->image_end_offset = high_off + cluster_size;
 322     if (size > res->image_end_offset) {
 323         int64_t count;
 324         count = DIV_ROUND_UP(size - res->image_end_offset, cluster_size);
 325         fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
 326                 fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
 327                 size - res->image_end_offset);
 328         res->leaks += count;
 329         if (fix & BDRV_FIX_LEAKS) {
 330             ret = bdrv_truncate(bs->file, res->image_end_offset);
 331             if (ret < 0) {
 332                 res->check_errors++;
 333                 return ret;
 334             }
 335             res->leaks_fixed += count;
 336         }
 337     }
 338
 339     return 0;
 340 }
 341
 342
 343 static int parallels_create(const char *filename, QemuOpts *opts, Error **errp)
 344 {
 345     int64_t total_size, cl_size;
 346     uint8_t tmp[BDRV_SECTOR_SIZE];
 347     Error *local_err = NULL;
 348     BlockDriverState *file;
 349     uint32_t bat_entries, bat_sectors;
 350     ParallelsHeader header;
 351     int ret;
 352
 353     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 354                           BDRV_SECTOR_SIZE);
 355     cl_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE,
 356                           DEFAULT_CLUSTER_SIZE), BDRV_SECTOR_SIZE);
 357
 358     ret = bdrv_create_file(filename, opts, &local_err);
 359     if (ret < 0) {
 360         error_propagate(errp, local_err);
 361         return ret;
 362     }
 363
 364     file = NULL;
 365     ret = bdrv_open(&file, filename, NULL, NULL,
 366                     BDRV_O_RDWR | BDRV_O_PROTOCOL, NULL, &local_err);
 367     if (ret < 0) {
 368         error_propagate(errp, local_err);
 369         return ret;
 370     }
 371     ret = bdrv_truncate(file, 0);
 372     if (ret < 0) {
 373         goto exit;
 374     }
 375
 376     bat_entries = DIV_ROUND_UP(total_size, cl_size);
 377     bat_sectors = DIV_ROUND_UP(bat_entries * sizeof(uint32_t) +
 378                                sizeof(ParallelsHeader), cl_size);
 379     bat_sectors = (bat_sectors *  cl_size) >> BDRV_SECTOR_BITS;
 380
 381     memset(&header, 0, sizeof(header));
 382     memcpy(header.magic, HEADER_MAGIC2, sizeof(header.magic));
 383     header.version = cpu_to_le32(HEADER_VERSION);
 384     /* don't care much about geometry, it is not used on image level */
 385     header.heads = cpu_to_le32(16);
 386     header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE / 16 / 32);
 387     header.tracks = cpu_to_le32(cl_size >> BDRV_SECTOR_BITS);
 388     header.bat_entries = cpu_to_le32(bat_entries);
 389     header.nb_sectors = cpu_to_le64(DIV_ROUND_UP(total_size, BDRV_SECTOR_SIZE));
 390     header.data_off = cpu_to_le32(bat_sectors);
 391
 392     /* write all the data */
 393     memset(tmp, 0, sizeof(tmp));
 394     memcpy(tmp, &header, sizeof(header));
 395
 396     ret = bdrv_pwrite(file, 0, tmp, BDRV_SECTOR_SIZE);
 397     if (ret < 0) {
 398         goto exit;
 399     }
 400     ret = bdrv_write_zeroes(file, 1, bat_sectors - 1, 0);
 401     if (ret < 0) {
 402         goto exit;
 403     }
 404     ret = 0;
 405
 406 done:
 407     bdrv_unref(file);
 408     return ret;
 409
 410 exit:
 411     error_setg_errno(errp, -ret, "Failed to create Parallels image");
 412     goto done;
 413 }
 414
 415
 416 static int parallels_probe(const uint8_t *buf, int buf_size,
 417                            const char *filename)
 418 {
 419     const ParallelsHeader *ph = (const void *)buf;
 420
 421     if (buf_size < sizeof(ParallelsHeader)) {
 422         return 0;
 423     }
 424
 425     if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
 426            !memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
 427            (le32_to_cpu(ph->version) == HEADER_VERSION)) {
 428         return 100;
 429     }
 430
 431     return 0;
 432 }
 433
 434 static int parallels_update_header(BlockDriverState *bs)
 435 {
 436     BDRVParallelsState *s = bs->opaque;
 437     unsigned size = MAX(bdrv_opt_mem_align(bs->file), sizeof(ParallelsHeader));
 438
 439     if (size > s->header_size) {
 440         size = s->header_size;
 441     }
 442     return bdrv_pwrite_sync(bs->file, 0, s->header, size);
 443 }
 444
 445 static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
 446                           Error **errp)
 447 {
 448     BDRVParallelsState *s = bs->opaque;
 449     ParallelsHeader ph;
 450     int ret, size;
 451
 452     ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
 453     if (ret < 0) {
 454         goto fail;
 455     }
 456
 457     bs->total_sectors = le64_to_cpu(ph.nb_sectors);
 458
 459     if (le32_to_cpu(ph.version) != HEADER_VERSION) {
 460         goto fail_format;
 461     }
 462     if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
 463         s->off_multiplier = 1;
 464         bs->total_sectors = 0xffffffff & bs->total_sectors;
 465     } else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
 466         s->off_multiplier = le32_to_cpu(ph.tracks);
 467     } else {
 468         goto fail_format;
 469     }
 470
 471     s->tracks = le32_to_cpu(ph.tracks);
 472     if (s->tracks == 0) {
 473         error_setg(errp, "Invalid image: Zero sectors per track");
 474         ret = -EINVAL;
 475         goto fail;
 476     }
 477     if (s->tracks > INT32_MAX/513) {
 478         error_setg(errp, "Invalid image: Too big cluster");
 479         ret = -EFBIG;
 480         goto fail;
 481     }
 482
 483     s->bat_size = le32_to_cpu(ph.bat_entries);
 484     if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
 485         error_setg(errp, "Catalog too large");
 486         ret = -EFBIG;
 487         goto fail;
 488     }
 489
 490     size = sizeof(ParallelsHeader) + sizeof(uint32_t) * s->bat_size;
 491     s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file));
 492     s->header = qemu_try_blockalign(bs->file, s->header_size);
 493     if (s->header == NULL) {
 494         ret = -ENOMEM;
 495         goto fail;
 496     }
 497     if (le32_to_cpu(ph.data_off) < s->header_size) {
 498         /* there is not enough unused space to fit to block align between BAT
 499            and actual data. We can't avoid read-modify-write... */
 500         s->header_size = size;
 501     }
 502
 503     ret = bdrv_pread(bs->file, 0, s->header, s->header_size);
 504     if (ret < 0) {
 505         goto fail;
 506     }
 507     s->bat_bitmap = (uint32_t *)(s->header + 1);
 508
 509     s->has_truncate = bdrv_has_zero_init(bs->file) &&
 510                       bdrv_truncate(bs->file, bdrv_getlength(bs->file)) == 0;
 511
 512     if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
 513         /* Image was not closed correctly. The check is mandatory */
 514         s->header_unclean = true;
 515         if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
 516             error_setg(errp, "parallels: Image was not closed correctly; "
 517                        "cannot be opened read/write");
 518             ret = -EACCES;
 519             goto fail;
 520         }
 521     }
 522
 523     if (flags & BDRV_O_RDWR) {
 524         s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
 525         ret = parallels_update_header(bs);
 526         if (ret < 0) {
 527             goto fail;
 528         }
 529     }
 530
 531     qemu_co_mutex_init(&s->lock);
 532     return 0;
 533
 534 fail_format:
 535     error_setg(errp, "Image not in Parallels format");
 536     ret = -EINVAL;
 537 fail:
 538     qemu_vfree(s->header);
 539     return ret;
 540 }
 541
 542
 543 static void parallels_close(BlockDriverState *bs)
 544 {
 545     BDRVParallelsState *s = bs->opaque;
 546
 547     if (bs->open_flags & BDRV_O_RDWR) {
 548         s->header->inuse = 0;
 549         parallels_update_header(bs);
 550     }
 551
 552     qemu_vfree(s->header);
 553 }
 554
 555 static QemuOptsList parallels_create_opts = {
 556     .name = "parallels-create-opts",
 557     .head = QTAILQ_HEAD_INITIALIZER(parallels_create_opts.head),
 558     .desc = {
 559         {
 560             .name = BLOCK_OPT_SIZE,
 561             .type = QEMU_OPT_SIZE,
 562             .help = "Virtual disk size",
 563         },
 564         {
 565             .name = BLOCK_OPT_CLUSTER_SIZE,
 566             .type = QEMU_OPT_SIZE,
 567             .help = "Parallels image cluster size",
 568             .def_value_str = stringify(DEFAULT_CLUSTER_SIZE),
 569         },
 570         { /* end of list */ }
 571     }
 572 };
 573
 574 static BlockDriver bdrv_parallels = {
 575     .format_name        = "parallels",
 576     .instance_size      = sizeof(BDRVParallelsState),
 577     .bdrv_probe         = parallels_probe,
 578     .bdrv_open          = parallels_open,
 579     .bdrv_close         = parallels_close,
 580     .bdrv_co_get_block_status = parallels_co_get_block_status,
 581     .bdrv_has_zero_init       = bdrv_has_zero_init_1,
 582     .bdrv_co_readv  = parallels_co_readv,
 583     .bdrv_co_writev = parallels_co_writev,
 584
 585     .bdrv_create    = parallels_create,
 586     .bdrv_check     = parallels_check,
 587     .create_opts    = &parallels_create_opts,
 588 };
 589
 590 static void bdrv_parallels_init(void)
 591 {
 592     bdrv_register(&bdrv_parallels);
 593 }
 594
 595 block_init(bdrv_parallels_init);